Lewis o hara



(No Modl.)

L. OHARA.

' LIFTING JACK. I No. 355,551. Patented Jan. 4, 1887.

I I i NVENTUF N. PETKRS. Hwlo-Liumgmphun Wuhinglon. 0.1:

UNITED STATES PATENT OF ICE.

L wIs OHARA, or OSWEGO, NEW YORK, ASSIGNOR OF ONE-HALF TO JOHN SINNAMON, OF sAME PLACE.

LlFTlNG-JACK.

SPECIPICATIONIorming part of Letters Patent No. 355,551, dated January 4, 1887.

. Aprlication filed October 16, 1886. Serial No. 216.382. (No molel.)

To all whom it may concern.-

Be it known that I, LEwIs OHARA, of Oswego, in the county of Oswego, in the State of New York, have invented new and useful Improvements in Lifting-Jacks, of which the following, taken-in connectionwith the accompanying drawings,'is a full, clear, and exact description. v

This invention relates to the class of liftingjacks in which a vertically sliding prop is guided on a standardand operated by a lever fulcrumed on a suitable support secured to said standard, and by toggle-arms connecting the short arm of the lever with the sliding 5 prop; and the invention has special reference to the liftingjack for which I have obtained Letters Patent of the United States, No. 164,323, dated June 8, 1875.

My present invention consists in an improved construction and combination of parts, whereby greater stability is imparted to the jack, as hereinafter fully described, and specifically set forth in the claims.

In the annexed drawings, Figure 1 is a side 5 elevation of my improved lifting-jack, and Fig. 2 is a vertical transverse section of the same.

Similar letters of reference indicate corresponding parts.

A represents the foot or base of the jack, preferably of the form of a hollow truncated cone terminating with a screw-threaded vertical socket, a, in the center of its upper end. In the socket a is supported the post P, which 5 has its lower end portion screw-threaded externally to work inthe socket a, and is thus rendered adjustable in its elevation.

On the upper end of the post 1? slides vertically a sleeve, 8, which is provided at its upper end with a broad horizontal cap, t. Some distance below the sleeve 8 is a collar, 1), rigidly secured to the post P, and from this collar rises an arm, I), on which is fulcrumed the hand-lever L. The short or upper arm of this lever is connected with the sliding sleeve 8 by toggle-arms O.

In operating the described.lifting-jack the post P is first turned in the socket act the base A, to raise or lower said post and bring it to the proper elevation to cause the sliding sleeve 8 to lift the superincumbent load when the sliding sleeve 8, thereby causing the lever and toggles to be locked in their said position by the downward pressure of the load supported by the jack.

In the lifting-jack shown in my prior patent,

hereinbefore referred to, the adjustable fea-' tures of the jack consist of a screw-threaded collar working on an externally screw-threaded hollow and stationary standard, and a prop slides in the hollow standard and is connected by toggle-arms with the aforesaid collar.

One of the defects of said prior device consists in the liability of the hollow standard becoming split by a lateral strain from a-load resting on the sliding prop when the leversupporting collar is screwed down on the standard, so as to leave a great portion of the latter unsupported by said collar, and this defect is obviated by my present invention. Another defect in the lifting-jack shown in my prior patent consists in the construction of the handlever and its connection with the collar 1), which necessitates cutting away the lower porpurpose of affording the requisite play to the lever. Said cutting away the material at the tion of the upright arm of the collar b for the junction of the arm with the collar b weakens the former, so as to cause it to break off when subjected to the pressure of the lever L' in lifting a load by the jack. To obviate this defect I now construct the lever L of a stout ferrule, 0, into which I insert a wooden handle, h. From said ferrule project two arms, d d, which are integral therewith and are pivoted on the collar-arm b, and have connected to them the toggles O, in the usual manner. The length of the arms d d from their fixed ends on the ferrule c to the pivot on the collar-arm b is somewhat greater than the height from the bottom of the collar 1) to the aforesaid pivot, so that the ferrule 0 passes under the aforesaid collar. when the lever is depressed, as represented in Fig. 2 of the drawings. This construetion allows me to maintain the arm b of a uniform size to the bottom of the collar 12,

the resultant projection on the side of the collar entering between the arms d d and over the ferrule c, as shown.

Having described myinvention,whatI claim as new, and desire to secure by Letters Patent, 1s v 1. The improved lifting-jack, consisting of the base A, provided with the screw-threaded socket a, the post I, screw-threaded at its lower end and adj ustably connected thereby to said socket, the sleeve 8, sliding on the upper end of the post and provided with the cap t, the collar 1), rigidly secured to the post, the lever L, fulcrumed on the collar, and the toggles 0, connecting the said lever with the sleeve 8, all constructed and combined substantially in the manner specified and shown.

2. In combination with the post P, sliding sleeves, toggles O, and the collar b, having the arm I) projecting from the side of said collar and maintained of uniform size to the bottom of the same, and the lever L, having the arms d d of greater lengths from their fixed ends to their pivot on the collar arm b than the height of said collar-arm from the bottom of the collar b to the aforesaid pivot, substantially as described and shown. i

In testimony whereof I have hereunto signed my name and alfixed my seal, in the presence of two attesting witnesses, at Oswego, in the county of Oswego, in the State of New York, this 9th day of October, 1886.

LEWVIS 'OHARA. [L. s.] Vitnesses:

T. H. WEBB, JOHN SINNAMON. 

